San Jose-based SoloPower celebrated the opening of its new flexible solar panel manufacturing plant in Portland today.

SoloPower’s solar panels look like long, laminated poster boards or shiny linoleum flooring. Actually, according to Chief Technology Officer Mustafa Pinarbasi, you can walk on them without doing any harm.

SoloPower's flexible solar panels starts out as a 6,000-foot sheet of stainless steel. A series of tools add materials to the sheet as it moves through the production line.

At the company’s new manufacturing plant in Portland, the panels start out as a 2,000 meter sheet of stainless steel wound around a spool. Machines add layers of material to the sheet over the course of 10 days.

The resulting roll of thin, bendable material is cut into solar panels that are five times lighter than the ones made with glass.

“We make the lightest solar panels per watt,” Pinarbasi said.

The advantage of lighter solar panels, Pinarbasi said, is you can put more of them on a large commercial or industrial roof without it caving in.

SoloPower panels are thin and flexible – a little bit like linoleum. At a celebration of the company's new plant in Portland today, people were welcome to stop on this panel on the floor.

“You want to be able to utilize all that roof space for this purpose,” he said. “But because of the weight, you can only utilize a certain number of panels. You can utilize five times more of the roof with our product.”

Company CEO Tim Harris said 70 percent of the commercial and industrial buildings in Portland and Seattle have rooftops that can’t handle the heavier panels. That’s a lot of potential customers.

“Our module weighs 13 pounds. A traditional module might weigh 55 pounds,” he said. “If you’re doing a standard size rooftop installation, the old technology would be the weight of a Boeing 737 on the roof. Ours would be the weight of a private jet. “

Some industry analysts say the SoloPower panels are unproven and too expensive given their level of efficiency.

The Oregonian reported skepticism from Fatima Toor, an industry analyst with Lux Research. She said she thinks only 10 to 15 percent of rooftops can’t handle conventional solar panels, that SoloPower’s panels only convert 10 percent of sunlight into electricity – in other words, they’re 10 percent efficient – while a competing panel is 12.5 percent efficient. She also estimated that SoloPower will spend $1.30 to $1.60 per watt producing panels compared with traditional panels that cost 65 to 70 cents per watt.

SoloPower CEO cut the ribbon on his company's new thin-film solar panel manufacturing plant in Portland today. The plant only has one of the four production lines that will be needed to fulfil the conditions of a federal loan guarantee.

But Pinarbasi said the SoloPower panels are less expensive to install than traditional panels and more efficiently produced, making them cost-competitive with all other panels on the market.

Harris said there’s already a lot of demand for his panels overseas. He expects two-thirds to three-fourths of the panels produced in Portland over the next year to be going overseas.

The company still has to add a second production line to its existing plant and two more lines in a nearby building to meet the requirements of a $197 million federal loan guarantee. Eventually, the company plans to have 400 megawatts of production capacity and 450 employees in Portland.

The company has also received a $10 million state loan, $20 million in state tax credits, and millions in tax incentives.